Liquid crystal display device

ABSTRACT

A pixel electrode formed into a slit structure with striped electrodes opposed to each other for a zero rubbing angle can provide fast response since rotational directions of the liquid crystals become opposite at both sides of the slit in the striped electrodes. The electrode structure, however, poses a problem of low transmittance. Provided is a liquid crystal display device of IPS-Pro scheme including a pixel electrode with one pair of striped electrodes. The first striped electrode includes a short electrode section and long electrode sections, and the second striped electrode also includes a short electrode section and long electrode sections. The long electrode sections of the first striped electrode are disposed adjacently to those of the second striped electrode. Liquid crystals are aligned in a lengthwise direction of the striped electrodes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.14/260,413, filed on Apr. 24, 2014, which claims the priority fromJapanese Patent Application No. 2013-92505 filed on Apr. 25, 2013 in theJapanese Patent Office, the entire contents of which are incorporatedherein by reference.

BACKGROUND

The present disclosure relates to a liquid crystal display device, whichcan be applied to a fast-response liquid crystal display mode, forexample.

Liquid crystal display devices are the displays of a non-light-emittingtype that display images by controlling the amount of light transmittedfrom a light source. Liquid crystal displays (LCDs) feature thin-walledand lightweight properties and low power consumption. In-Plane Switching(IPS) is among the typical liquid crystal display schemes currentlyuseable to attain a wide viewing angle. The IPS scheme is a liquidcrystal driving scheme that rotates liquid crystal molecules in a planardirection via a horizontal (in-plane) electric field, thus rotates aneffective optical axis within a plane, and controls transmittance of thelight. Various methods have heretofore been proposed for applying thehorizontal electric field. The most common method is by forming a pixelelectrode and a common electrode on one substrate with a stripeelectrode structure. The application of the horizontal electric fieldwith the stripe electrode structure is accomplished by, for example,forming both of the pixel electrode and the common electrode into thestripe electrode structure, or forming only the pixel electrode into thestripe electrode structure and disposing the common electrode of a flatshape via an insulating layer. Among the methods for applying theelectric field are, for example, IPS-Pro (Provectus), which is describedin JP-A-2009-150945, and Fringe Field Switching (FFS), which isdescribed in JP-A-2010-19873.

SUMMARY

The present inventors initially considered adopting a fast-responseliquid crystal display mode in the IPS-Pro scheme. The inventors,however, found the following problem:

Forming a pixel electrode into a slit structure including stripedelectrodes opposed to each other for a zero rubbing angle enables fastresponse since rotational directions of the liquid crystals becomeopposite at both sides of the slit in the striped electrodes. Theelectrode structure, however, poses a problem of low transmittance.

Some of typical features and characteristics of the present disclosureare outlined below.

The pixel electrode of a liquid crystal display device includes one pairof striped electrodes. A first striped electrode includes a shortelectrode section and long electrode sections, and a second stripedelectrode also includes a short electrode section and long electrodesections. The long electrode sections of the first striped electrode isdisposed adjacently to those of the second striped electrode. Liquidcrystals are aligned in a lengthwise direction of the stripedelectrodes.

The liquid crystal display device has fast response characteristics, andyet it can raise transmittance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a general IPS-Pro structure in a liquidcrystal display device;

FIG. 2 is a plan view of a pixel structure of a liquid crystal displaydevice according to a comparative example;

FIG. 3A is a sectional view of an electrode structure of the liquidcrystal display device according to the comparative example, and FIG. 3Bis a plan view of the electrode structure;

FIGS. 4A and 4B are explanatory diagrams illustrating the operationprinciple of the liquid crystal display device according to thecomparative example;

FIG. 5 is an explanatory diagram illustrating how the liquid crystaldisplay device according to the comparative example reducestransmittance;

FIG. 6 is a diagram showing an electrode structure of a liquid crystaldisplay device according to an example;

FIG. 7 is a diagram that shows places where a disclination occurs in theelectrode structure of the liquid crystal display device according tothe example;

FIGS. 8A and 8B are diagrams that show measurement results onvoltage-luminance characteristics of the electrode structure of theliquid crystal display device according to the comparative example, andthose of the electrode structure of the liquid crystal display deviceaccording to the example;

FIG. 9 is a diagram that shows simulation results on electro-opticresponse of a conventional liquid crystal display device of the IPS-Proscheme and the liquid crystal display device according to the example;

FIG. 10 is a diagram showing an electrode structure of a liquid crystaldisplay device according to a first modification; and

FIG. 11 is a diagram showing an electrode structure of a liquid crystaldisplay device according to a second modification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereunder, an example and modifications of the present invention, and acomparative example will be described in detail, pursuant to theaccompanying drawings. In all of the drawings illustrating the example,the modifications, and the comparative example, elements having the samefunction are each assigned the same reference number, and repeateddescription of these elements is omitted hereinafter.

While alignment of liquid crystals (initial alignment of the liquidcrystals) is obtained by a rubbing method in the following description,photo-alignment or any other appropriate alignment method may be usedinstead.

Prior to the present disclosure, the present inventors initiallyconsidered adopting the fast-response liquid crystal display mode in theIPS-Pro scheme. The inventors, however, found a problem. The followingdescribes the problem.

First, a liquid crystal display device of a general IPS-Pro structure isdescribed here. FIG. 1 shows schematically a section of one pixel in theliquid crystal display device of the general IPS-Pro structure. Theliquid crystal display device is constituted mainly by a first substrateSU1, a second substrate SU2, and a liquid crystal layer LCL. The firstsubstrate SU1 and the second substrate SU2 hold the liquid crystal layerLCL sandwiched between both. In order to stabilize an aligned state ofthe liquid crystal layer LCL, the first substrate SU1 and the secondsubstrate SU2 include a first alignment film AL1 and a second alignmentfilm AL2, respectively, on surfaces close to the liquid crystal layerLCL. Means for applying a voltage to the liquid crystal layer LCL isalso present on a surface of the second substrate SU2 that is close tothe liquid crystal layer LCL. A first polarizer PL1 is mounted above thefirst substrate SU1, and a second polarizer PL2 above the secondsubstrate SU2.

The first substrate SU1 is a glass substrate. A first alignment filmAL1, a leveling layer LL, a color filter CF, and a black matrix BM arestacked in that order between the first substrate SU1 and the liquidcrystal layer LCL. The first alignment film AL1 is apolyimide-containing organic high-polymer film and is a horizontalalignment film. The leveling layer LL is an acrylic resin, excels intransparency, and has a function that levels out surface irregularitiesof an underlayer and prevents penetration of a solvent. The color filterCF has a flat structure with a repeated array of striped elementsassuming red, green, and blue colors. The black matrix is formed from aresist including a black pigment, and has a planarly distributedstructure of a grid-like shape, geared to identify pixel boundaries. Inaddition, a backside electrode BE for antistatic purposes is disposed ona side of the first substrate SU1 that is opposite to a side on whichthe liquid crystal layer LCL is disposed. The backside electrode BE ismade from an indium-tin oxide (ITO) that exhibits a planar distributionof a flat form.

The second substrate SU2 is a glass substrate, as with the firstsubstrate SU1. A second alignment film AL2, a pixel electrode PE, aninterlayer insulating film PCIL, a common electrode CE, an activeelement (not shown), a gate line GL, and a source line SL are mainelements provided between the second substrate SU2 and the liquidcrystal layer LCL. The second alignment film AL2, as with the firstalignment film AL1, is a horizontal alignment film formed from apolyimide-containing organic high-polymer film. The pixel electrode PEand the common electrode CE are both made from an ITO that excels intransparency and electric conduction properties. Both PE and CE areseparated from each other by the interlayer insulating film PCIL made ofsilicon nitride (SiN). Whereas the pixel electrode PE is striped in flatshape, the common electrode CE has a contact hole CH, but is distributedover a substantially entire pixel surface. A gate line insulating filmCIL is disposed on the gate line GL, the source line SL on the gate lineinsulating film CIL, and a common electrode insulating film CEIL on thegate line insulating film CIL and the source line SL.

Since the pixel electrode structure in FIG. 1 is most important in thepresent disclosure, only the pixel electrode PE, the interlayerinsulating film PCIL, and the common electrode CE will be describedhereinafter. The pixel electrode shape and liquid crystal alignmentdirection of the liquid crystal display device in the IPS-Pro structure(comparative example) whose adoption was considered prior to the presentdisclosure, and those of the liquid crystal display device of theexample differ from the pixel electrode shape and liquid crystalalignment direction of the liquid crystal display device, shown inFIG. 1. In other structural aspects, however, the former two liquidcrystal display devices are substantially the same as in FIG. 1. WhileFIG. 1 corresponds to an S1-S2 section in FIG. 2, the shape of the pixelelectrode and the direction in which the liquid crystals are aligneddiffer from those of FIG. 2.

FIG. 2 is a plan view of a pixel structure of the liquid crystal displaydevice according to the comparative example. As shown in FIG. 2, thepixel electrode PE is rectangular in flat shape and has a slit 1 and acontact hole CH. The pixel electrode PE constitutes one pair of stripedelectrode sections with the slit 1. The striped electrode sections ofthe pixel electrode PE are formed so that a lengthwise direction of eachis parallel to an X-direction in which a gate line GL extends. Inaddition, the left-and-right pair of striped electrode sections areformed to be shifted in position from each other by substantially half apitch in FIG. 2. The common electrode CE, which is present at a positionlower than that of the pixel electrode PE, has a contact hole CH notshown, but is distributed over a substantially entire pixel surface.Outside the pixel electrode PE, a source line SL extends in alongitudinal direction (Y-direction) of the electrode PE. In addition,outside the pixel electrode PE, a gate line GL extends in a lateraldirection (X-direction) of the electrode PE. A thin-film transistor TFTas an active element, is present at a position lower than that of thecommon electrode CE.

FIGS. 3A and 3B are enlarged views of a region D in the electrodestructure of FIG. 2. FIG. 3A is a sectional view of an A-A′ line in FIG.3B, and FIG. 3B is a plan view. The pixel electrode PE is disposed abovethe common electrode CE via an interlayer insulating film PCIL. Arubbing direction, which is a liquid crystal alignment direction, isparallel to the lengthwise direction of the striped electrode sectionsof the pixel electrode PE. The pair of upper and lower striped electrodesections are formed to be shifted in position from each other bysubstantially half a pitch in FIG. 3B. A line connecting a distal end ofeach upper striped electrode section is separate from a line connectinga distal end of each lower striped electrode section.

FIGS. 4A and 4B are explanatory diagrams illustrating the way the liquidcrystal display device according to the comparative example operates.FIGS. 4A and 4B are drawings showing only a region B of FIG. 3B. FIG. 4Ashows directions of an electric field, and FIG. 4B shows rotationaldirections of the liquid crystals. The rubbing direction, or thealignment direction of the liquid crystals, is parallel to thelengthwise direction of the striped electrode sections of the pixelelectrode PE, and the liquid crystal is made of a material that has apositive dielectric anisotropy. Thus, the liquid crystals between thestriped electrode sections have equal force for clockwise andcounterclockwise rotation, so that the respective rotational directionsare not determinate. As indicated by the direction EL of the electricfield in FIG. 4A, therefore, the electric field at edges or bases of thestriped electrode sections is rendered oblique with respect to theelectrode. As indicated by the rotational direction LR of the liquidcrystals in FIG. 4B, the directions in which the liquid crystals rotateare determined based on the oblique field. Thus, the liquid crystalsrotate in two different directions between the striped electrodes. Atthis time, regions in which the liquid crystals rotate in the samedirection become small, compared with those of the conventional IPS-Proor FFS schemes, and consequently, the aligned liquid crystals aresignificantly distorted, increase in resilience, and can be driven at ahigher speed.

FIG. 5 is an explanatory drawing that illustrates how the liquid crystaldisplay device according to the comparative example reducestransmittance. In a case that the liquid crystals differ in rotationaldirection, disclinations occur at the boundaries. In the electrodestructure based on the IPS-Pro technology whose adoption was consideredprior to the present disclosure, disclination lines DL, denotegeneration of black lines, ought to occur during voltage application, asshown in FIG. 5. Sufficient transmittance cannot be obtained at wherethe disclination lines DL occur.

The liquid crystal display device according to the comparative example,therefore, poses a problem that while fast response can be obtained,transmittance is low.

To deal with the above problem, the structure of the pixel electrode wasstudied. A liquid crystal display device according to an embodimentincludes a common electrode having a structure of a flat shape, and apixel electrode. The pixel electrode includes one pair of stripedelectrodes. A first striped electrode includes a short electrode sectionand long electrode sections, and a second striped electrode alsoincludes a short electrode section and long electrode sections. The longelectrode sections of the first striped electrode is disposed adjacentlyto those of the second striped electrode. Liquid crystals are initiallyoriented in a lengthwise direction of the striped electrodes. The liquidcrystal display device according to the embodiment has fast responsecharacteristics, and yet the device can raise transmittance. Hereunder,the embodiment will be described in detail using an example.

(Example)

As described above, the pixel electrode shape and liquid crystalalignment direction of the liquid crystal display device according tothe example differ from those of the liquid crystal display device,shown in FIG. 1. In terms of other structural aspects, however, theliquid crystal display device of the example is substantially the sameas in FIG. 1.

FIG. 6 is an external view showing an electrode structure of the liquidcrystal display device according to the example. As shown in FIG. 6,although the pair of striped electrodes are disposed with a shift inposition of half a pitch, the short electrode sections and the longelectrode sections are combined to shift a position of a slit. Forleft-right balancing, the pair of striped electrodes are preferablyshifted in position from each other by exactly half a pitch, but do notalways need to be shifted in position by exactly half a pitch. The firststriped electrode includes a short electrode section and a pair of longelectrode sections adjacent to the short electrode section. The secondstriped electrode also includes a short electrode section and a pair oflong electrode sections adjacent to the short electrode section. It isvital that the long electrode sections of the first striped electrode beadjacent to those of the second striped electrode, and that the slitextending in an X-direction be divided. The planar structure of thepixel electrode PE is described in further detail below.

The first striped electrode includes a short electrode section E1 a andlong electrode sections E1 b and E1 c each extending in the X-direction,and an electrode section E1 that couples the electrode sections E1 a, E1b, E1 c at one end of each and extends in a Y-direction. The secondstriped electrode includes a short electrode section E2 a and longelectrode sections E2 b and E2 c each extending in the X-direction, andan electrode section E2 that couples the electrode sections E2 a, E2 b,E2 c at one end of each and extends in the Y-direction. These short andlong electrodes E1 a, E1 b, E1 c, E2 a, E2 b, and E2 c are each of arectangular shape, and are placed between the electrode sections E1 andE2. The other end (distal end) of each of the short electrode section E1a and the long electrode sections E1 b, E1 c faces the electrode sectionE2, and the other end (distal end) of each of the short electrodesection E2 a and the long electrode sections E2 b, E2 c faces theelectrode section E1. The electrode section E1 and the electrode sectionE2 are disposed at alternate positions. The distal end of the shortelectrode section E1 a faces the electrode section E2 between theadjacent long electrode sections E2 b and E2 c. The distal end of theshort electrode section E2 a faces the electrode section E1 between theadjacent long electrode sections E1 b and E1 c.

If a distance between the electrode sections E1 and E2 is taken as L,length of the short electrode section E1 a as L1 a, length of the longelectrode section E2 b as L2 b, and length of the long electrode sectionE2 c as L2 c, then it follows thatL2b>L/2>L1a,L>L1a+L2b, andL2c>L/2>L1a,L>L1a+L2c,where L2 b=L2 c may hold. If length of the short electrode section E2 ais taken as L2 a, length of the long electrode section E1 b as L1 b, andlength of the long electrode section E1 c as L1 c, then it follows thatL1b>L/2>L2a,L>L1b+L2a, andL1c>L/2>L2a,L>L1c+L2a,where L1 b=L1 c may hold. Additionally or alternatively, L1 a=L2 a, L1b=L1 c=L2 b=L2 c may hold. The pixel electrode PE is formed in aniterative pattern with W of FIG. 6 as a period.

The pixel electrode PE of the rectangular shape has a slit to constitutethe pair of striped electrodes, as in the comparative example. The shortelectrode section E1 a, the long electrode sections E1 b, E1 c, theshort electrode section E2 a, and the long electrode sections E2 b, E2 cneed only to extend in the same direction and do not always need toextend exactly in the X-direction.

With the pixel electrode structure according to the example, theoccurrence of a reverse domain that has been observed in the comparativeexample can be suppressed and transmittance can be improved. The reversedomain is a region in which the rotational direction of the liquidcrystals during voltage application is reverse to that of the liquidcrystals in a central portion of pixels. If the reverse domain occurs,an alignment change that causes clockwise rotation becomes balanced withan alignment change that causes counterclockwise rotation, andconsequently a region in which no alignment change occurs is generatedin the pixel. The region where no alignment change occurs indicatessubstantially the same alignment state as that of dark display, so theregion is observed as disclinations or dark lines, which reducetransmittance. Forming long electrodes adjacent to one short electrodeoffers an advantageous effect.

Except for shape, the striped electrode sections of the pixel electrodePE are substantially the same as those of the structure in thecomparative example. More specifically, except for shape, the stripedelectrode sections in FIGS. 2, 3A, 3B are substantially of the samepixel structure as in the example. A rubbing direction, or the directionin which the liquid crystals are aligned, is parallel to a lengthwisedirection of the striped electrode sections of the pixel electrode PE,as in the comparative example. The striped electrode sections of thepixel electrode PE are formed so that the lengthwise direction(X-direction) of each is parallel to the X-direction in which a gateline GL extends. The lengthwise direction (X-direction) of each stripedelectrode section of the pixel electrode PE, however, needs only to beparallel to each other and does not always need to be parallel to theX-direction in which the gate line GL extends.

FIG. 7 is a drawing that shows places in which a disclination occurs, inthe electrode structure of the liquid crystal display device accordingto the example. As can be seen by comparing FIGS. 7 and 5, the number ofplaces where the disclination occurs is reduced in the example. Thus,transmittance can be raised.

FIGS. 8A and 8B are diagrams that show simulation results onelectro-optic response of the conventional liquid crystal display deviceof the IPS-Pro scheme and the liquid crystal display device according tothe example. Both devices are made from liquid crystal materials havingthe same physical properties. FIG. 8A shows a fall time up to turn-offof the device, and FIG. 8B shows a rise time up to turn-on of thedevice. As is evident from the simulation results, the electrodestructure of the example provides rapid driving of the liquid crystals.More specifically, as shown in FIG. 8A, the conventional IPS-Pro scheme(shown as IPS-Pro in FIGS. 8A and 8B) requires a fall time of about 25msec at a 100%-10% response signal level, whereas the example requiresonly a fall time of about 6 msec at the same response signal level asthe above. This means that the example implements more rapid drivingthan the conventional IPS-Pro scheme does. It can also be seen from FIG.8B that at a 0%-90% response signal level, whereas the conventionalIPS-Pro scheme requires a rise time of about 26 msec, the examplerequires only a rise time of about 10 msec, which means that the exampleimplements more rapid driving than the conventional IPS-Pro scheme does.As in FIG. 4B, the liquid crystals rotate in two different directionsbetween the striped electrodes. Thus, regions in which the liquidcrystals rotate in the same direction become small, compared with thoseof the conventional IPS-Pro or FFS schemes, and consequently, thealigned liquid crystals are significantly distorted, increase inresilience, and can be driven at a higher speed.

FIG. 9 is a drawing that shows measurement results on voltage-luminancecharacteristics of a cell with the electrode structure of the liquidcrystal display device according to the comparative example, and a cellwith the electrode structure of the liquid crystal display deviceaccording to the example. FIG. 9 indicates that the electrode structureof the liquid crystal display device according to the example improvesluminance.

In the liquid crystal display device according to the example, as in thecomparative example, rapid driving can be realized since the rotationaldirections of the liquid crystals become opposite at both sides of theslit in the striped electrodes of the pixel electrode. In other words,rapid driving can be realized since the rotational directions of theliquid crystals become opposite at both sides of the slit in the stripedelectrodes of the pixel electrode. In addition, the occurrence of areverse domain in the comparative example can be suppressed in theexample of the present invention and transmittance can be improved.

Since the liquid crystal display device according to the example canrespond rapidly, the display device can be applied as a vehicle-mountedliquid crystal display device. Additionally, since video performanceimproves, the display device can be applied as a liquid crystal displaydevice for a smartphone or tablet terminal.

(First Modification)

FIG. 10 is a drawing showing an electrode structure of a liquid crystaldisplay device according to a first modification. As shown in FIG. 10,if a spacing between the long electrode sections E2 b and E2 c and aspacing between the long electrode sections E1 b and E1 c are both takenas “a”, and a spacing between the short electrode section E2 a and thelong electrode section E2 c and a spacing between the short electrodesection E1 a and the long electrode section E1 c are both taken as “b”,then “a<b” holds in the pixel electrode structure of the liquid crystaldisplay device according to the first modification. In the pixelelectrode structure of the liquid crystal display device according tothe example, “a≧b” holds. Other pixel-electrode structural aspects arethe same as those of the example. In the example, the occurrence ofdisclinations has been observed between a short electrode section andlong electrode sections. In the first modification, however, occurrenceof disclinations can be suppressed since the distal end of the shortelectrode section E2 a can be brought close to those of the longelectrode sections E1 b and E1 c and since the distal end of the shortelectrode section E1 a can be brought close to those of the longelectrode sections E2 b and E2 c. The pixel electrode structure of theliquid crystal display device according to the first modification willtherefore provide higher transmittance than the pixel electrodestructure of the liquid crystal display device according to the example.A spacing between the long electrode section E1 c and the long electrodesection E2 c is greater than in the example.

(Second Modification)

FIG. 11 is a drawing showing a pixel electrode structure of, anddirections of an electric field in, a liquid crystal display deviceaccording to a second modification. The pixel electrode structure of theliquid crystal display device according to the second modificationdiffers from the structure of the first modification in FIG. 10 in thatas shown in FIG. 11, short electrode sections are nested between longelectrode sections. Other pixel-electrode structural aspects are thesame as those of the first modification. The short electrode section E1a is nested between the long electrode sections E2 b and E2 c, and theshort electrode section E2 a is nested between the long electrodesections E1 b and E1 c. The nested structure makes liquid crystals movemore smoothly. Thus the occurrence of disclinations that has beenobserved in the slit can be suppressed and transmittance can beimproved. An advantageous effect can be obtained if nesting length Cexceeds or equal to 0. The pixel electrode structure of the liquidcrystal display device according to the second modification willtherefore provide higher transmittance than the pixel electrodestructures of the liquid crystal display devices according to theexample and the first modification. Relationships of L=L1 a+L2 b−C, L=L1a+L2 c−C, L=L1 b+L2 a−C, L=L1 c+L2 a−C are established in the secondmodification. In addition, the long electrode section E1 c is nestedbetween the short electrode section E2 a and the long electrode sectionE2 c, and the long electrode section E2 c is nested between shortelectrode section E1 a and the long electrode section E1 c.

While the invention achieved by the present inventors has been describedin detail above on the basis of the embodiment, the example, and themodifications, it goes without saying that the invention is not limitedto the embodiment, the example, and the modifications, and may bechanged or modified in various forms.

What is claimed is:
 1. A liquid crystal display device, comprising: acommon electrode having a flat structure; a pixel electrode disposedabove the common electrode via an insulating film; an alignment filmdisposed on the pixel electrode; and a liquid crystal layer disposed onthe alignment film, wherein the pixel electrode includes one pair ofstriped electrodes, a first striped electrode of the striped electrodespair includes a short electrode section, a second striped electrode ofthe striped electrodes pair includes a plurality of long electrodesections, the short electrode section belonging to the first stripedelectrode is disposed at an opposed position with respect to the longelectrode sections belonging to the second striped electrode, the shortelectrode sections of the first striped electrodes are shorter than thelong electrode sections of the second striped electrodes, and liquidcrystals are aligned in a lengthwise direction of the stripedelectrodes.
 2. The liquid crystal display device according to claim 1,wherein the pixel electrode has a slit to constitute the pair of stripedelectrodes.
 3. The liquid crystal display device according to claim 1,wherein the pixel electrode includes a contact hole in a place differentfrom where the slit is located, the common electrode includes a hole,and the hole is close to the contact hole.
 4. The liquid crystal displaydevice according to claim 1, further comprising a gate line, wherein thelengthwise direction of the striped electrodes is parallel to adirection in which the gate line extends.
 5. The liquid crystal displaydevice according to claim 1, further comprising a source line, whereinthe lengthwise direction of the striped electrodes is orthogonal to adirection in which the source line extends.
 6. The liquid crystaldisplay device according to claim 1, wherein the liquid crystal layer ismade from a material that has a positive dielectric anisotropy.
 7. Theliquid crystal display device according to claim 1, wherein, of thefirst striped electrode, a distance between the adjacent two longelectrode sections is shorter than a distance between the adjacent longand short electrode sections.
 8. The liquid crystal display deviceaccording to claim 7, wherein the short electrode section belonging tothe first striped electrode is nested between the adjacent longelectrode sections belonging to the second striped electrode.
 9. Aliquid crystal display device, comprising: a common electrode having aflat structure; a pixel electrode disposed above the common electrodevia an insulating film; an alignment film disposed on the pixelelectrode; and a liquid crystal layer disposed on the alignment film,wherein the pixel electrode includes a first striped electrode and asecond striped electrode, the first striped electrode includes a firstelectrode section extending in a first direction, and a first shortelectrode section extending from the first electrode section to a seconddirection crossing the first direction, the second striped electrodeincludes a second electrode section extending in a first direction, anda fifth long electrode section, and a sixth long electrode section, eachextending from the second electrode section to the second direction, thefirst short electrode section has a distal end disposed at an opposedposition with respect to the second electrode section between the secondlong electrode section and the third long electrode section, the firstshort electrode section is shorter than, the second long electrodesection, and the third long electrode section, and liquid crystals arealigned in the second direction.
 10. The liquid crystal display deviceaccording to claim 9, wherein the first direction and the seconddirection are orthogonal to each other.
 11. The liquid crystal displaydevice according to claim 9, wherein the pixel electrode has a slit toconstitute the first striped electrode and the second striped electrode.12. The liquid crystal display device according to claim 9, wherein thepixel electrode includes a contact hole in a place different from wherethe slit is located, the common electrode includes a hole, and the holeis close to the contact hole.
 13. The liquid crystal display deviceaccording to claim 9, further comprising a gate line extended in thefirst direction.
 14. The liquid crystal display device according toclaim 9, further comprising a source line extended in the seconddirection.
 15. The liquid crystal display device according to claim 9,wherein the liquid crystal layer is made from a material that has apositive dielectric anisotropy.